Huge Asian carp kill reported below Barkley Dam; biologist seek cause

Jumping silver carp have been known to injure boaters.

There’s the old saying, “I've got good news and I’ve got bad news. Which do you want first?”

Well, the word from the Cumberland River below Lake Barkley is, “I ‘I've got some good news and some news with questions.” 

The good news that what probably is the greatest Asian Carp fish kill in U.S. history has just taken place below the Lake Barkley Dam. There may not be any bad news, but the question remains as to what caused the kill. And some folks in a somewhat joking matter are wondering if the kill could be duplicated elsewhere.

The Asian carp is an invasive species apparently accidentally released in this country that is not only causing problems for sports fish, but also in some cases are dangerous to human boaters as well. Very little commercial use has been found for these fish.

Numerous reports of the fish jumping and hitting boaters and causing injury have been made in recent years, including several from the Ohio River and Perry County’s Oil Creek in Indiana.

It is believed that somewhere between 300,000 and 500,000 of the carp died below the dam. and it is believed the die-off has peaked and may be over.

According to information from the Kentucky Department of Fish & Wildlife Resources, on Friday, April 25, KDFWR fisheries biologists returned to the area as the focus shifted to learning what might have caused the considerable die-off of invasive silver carp.

“Anglers were seeing dead fish a week ago, some two weeks ago, which is very typical of a fish kill caused by some type of viral pathogen,” said Paul Rister, western fisheries district biologist with Kentucky Fish and Wildlife. “It’s kind of a bell-shaped curve. You start seeing a few die, and a few more die, and then you reach the peak of the massive die-off. I think we’re on that downhill side now.”

After conferring with Asian carp researchers from around the country, Kentucky Fish and Wildlife Fisheries Director Ron Brooks said the belief among experts is that the fish kill found below Barkley Dam to the Cumberland River’s confluence with the Ohio River is the largest ever involving Asian carp in the United States.

Silver carp, which are not native to the United States, appear to be the only fish affected. 

To help move the mass of fish downriver, the U.S. Corps of Engineers opened three gates at Barkley Dam to flush dead fish downstream.

“I don’t think people have to worry about those pathogens affecting native species,” Brooks said. “That’s probably the best news of all.”

While the cause has not been confirmed, possibilities include overstress from spawning or the presence of a pathogen that disrupts brain function in the fish, Brooks said.

“Any time you have an event where there are a lot of fish congregating, it’s just like any other animal, the chance for a pathogen to spread increases,” he said. “Whether it’s that pathogen or some other stressor, no one will know until we get word from the researchers.”

Dying silver carp collected from the area by Kentucky Fish and Wildlife will undergo disease testing at Kentucky State University. Kentucky Fish and Wildlife also is working the U.S. Fish and Wildlife Service as well as agencies from bordering states, including Indiana’s Purdue University.